General equilibrium analysis
General equilibrium analysis is an approach that considers simultaneously all
the markets and feedback effects among these markets in an economy leading to
market clearance. See also market equilibrium.

Geo-engineering
Efforts to stabilise the climate system by directly managing the energy balance
of the earth, thereby overcoming the enhanced greenhouse effect.

GHG See greenhouse gas.

Global warming
Global warming is an observed or projected increase in global average temperature.

Global Warming Potential (GWP)
An index, describing the radiative characteristics of well-mixed greenhouse
gases, that represents the combined effect of the differing times these
gases remain in the atmosphere and their relative effectiveness in absorbing
outgoing infrared radiation. This index approximates the time-integrated warming
effect of a unit mass of a given greenhouse gas in todays atmosphere,
relative to that of carbon dioxide. Note that GWP also
stands for Gross World Product.

GNPSee Gross National Product.

GPPSee Gross Primary Production.

Greenhouse effectGreenhouse gases effectively absorb infrared radiation emitted
by the earths surface, by the atmosphere itself from these same gases,
and by clouds. Atmospheric radiation is emitted to all sides, including downwards
to the earths surface. Thus, greenhouse gases trap heat within
the surfacetroposphere system. This is called the natural greenhouse effect.
Atmospheric radiation is strongly coupled to the temperature of the level at
which it is emitted. In the troposphere the temperature generally decreases
with height. Effectively, infrared radiation emitted to space originates from
an altitude with a temperature of, on average, 19°C, in balance with
the net incoming solar radiation. However, the earths surface is kept
at a much higher temperature of on average +14°C. An increase in the concentration
of greenhouse gases leads to an increased infrared opacity of the atmosphere,
and therefore to an effective radiation into space from a higher altitude at
a lower temperature. This causes a radiative forcing, an imbalance
that can only be compensated for by an increase in the temperature of the surfacetroposphere
system. This is the enhanced greenhouse effect.

Greenhouse gas (GHG)Greenhouse gases are those gaseous constituents of the atmosphere, both
natural and anthropogenic, that absorb and emit radiation at specific wavelengths
within the spectrum of infrared radiation emitted by the earths surface,
the atmosphere, and clouds. This property causes the greenhouse effect.
Water vapour (H2O), carbon dioxide, nitrous oxide, methane
and ozone (O3) are the primary greenhouse gases
in the earths atmosphere. Moreover, there are a number of entirely human-made
greenhouse gases in the atmosphere, such as the halocarbons and other
chlorine- and bromine-containing substances, dealt with under the Montreal
protocol. Beside carbon dioxide, nitrous oxide and methane,
the Kyoto Protocol deals with the greenhouse gasessulphur
hexafluoride, hydrofluorocarbons, and perfluorocarbons.

Gross World Product (GWP)
An aggregation of the Gross Domestic Products of the world. Note
that GWP also stands for Global Warming Potential.

Gross Domestic Product (GDP)
The sum of gross value added, at purchasers prices, by all
resident and non-resident producers in the economy, plus any taxes and minus
any subsidies not included in the value of the products in a country or a geographic
region for a given period of time, normally 1 year. It is calculated without
deducting for depreciation of fabricated assets or depletion and degradation
of natural resources

Gross National Product (GNP)
GNP is a measure of national income. It measures value added from
domestic and foreign sources claimed by residents. GNP comprises Gross
Domestic Product plus net receipts of primary income from non-resident
income.

Gross Primary Production (GPP)
The amount of carbon fixed from the atmosphere through photosynthesis.

Group of 77 and China (G77/China)
Originally 77, now more than 130 developing countries that act as a major negotiating
bloc in the UNFCCC (United Nations Framework Convention on Climate Change)
process. G77/China is also referred to as non-Annex I countries
in the context of the United Nations Framework Convention on Climate Change.